Roller coaster/war

So, recently I've been accusing the girls of tag-teaming me in the sleep/crying department. Each of them seems to be on their own separate roller coaster. For a couple of nights last week they simply staggered their awake time at night--if Ellen was up from 1-2 to eat, Emily would wake up at 3. Then Ellen would be back up at 4 or 5... Emily generally just wakes up and comes in our room and has to be put back--her "episodes" only require leaving the bed for a couple of minutes (but I'm woken up, nonetheless). Apparently this is retribution for similar crimes that I committed when I was her age. However, there were a few nights when they were really out to get me. One night Emily would have her quick awake period(s), and Ellen would have a marathon awake time of 2+ hours. Then the next night Ellen would be an awesome sleeper with even 5 hours between feedings, but Emily would have a marathon awake time of 2+ hours. Weird. I'm almost hesitant to say that we've had okay nights the last two nights--Emily has been up only once (I think), which I can handle, and Ellen has eaten & returned to bed in a reasonable amount of time. Ellen had a rather colicky day yesterday (she wanted to be held nonstop, and only slept when Jon held her), but again, slept well at night. One day I'll figure it all out, and they'll both sleep all night.